San Francisco (Calif.). Board of Supervisors.

The municipal employee (Volume v.3 (Jan. - Sept. 1929)) online

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building accommodates cable reels and
overhead construction material.

Fire Alarm Systems
The fire alarm system in 1900 con-
sisted of a few signal circuits which
were connected to the station by open
wire overhead construction, a more or
less antiquated switchboard and a room
filled with a few hundred cells of wet
batter)% which were transformed into
a mass of broken jars at the first shake
of the earthquake in 1906. leaving the
entire city without fire alarm service.
The fire alarm system in service to-
day is one of the most efficient and up-
to-date systems in the United States,
and is what is known as the "manual"
system, and, due to the fact that the

fire alarm bo.xes have a speed of be-
tween five and six l)l()ws a second and
the alarms are "struck out" to the en-
gine houses at the rate of between two
and three blows a secotid, it is one of
the fastest, if not the fastest fire alarm
signalling system in any city in the
United States. The average box re-
quires only twenty-three seconds from
the time a citizen pulls in an alann
from a box before the apparatus has
started to "roll" to the scene of the

The Central Fire Alarm station in
Jefferson .Square has a minimum dis-
tance of 300 feet to the nearest line of
buildings, and. should the city be un-

f(jrtunate enough to experience another
fire such as in 1906, the entire area
surrounding the station could be de-
stroyed without affecting the station.
The e<|uipment was manufactured
and installed by the Department
iif Electricity and the station was
l^laced in service February 5, 1915. The
station is of reinforced concrete con-
struction, having no openings on three
sides, and is a low structure designed
with such a margin of safety as to
withstand the most severe earthquake.
The storage batteries occupy a room
on the ground floor and the room is so
designed that a severe shake would
have little or no effect on the batteries.

Jt the lop is till- duflicate Stt of Teletype transmitterj, located in the Detective
Bureau at the Hall of Justice. The bottom picture shov-s the police telephone signal
board, left — and at right, the Teletype receiver furnished by the Sierra Equipment
Corporation, San Francisco. This mechanism has just been installed at the ne<ii;
Tarai'al Police Station. Station Keeper Ed^i-ard Cough at the 'phone.



yietus of the City's new traffic signals, designed by Chief Ralph W . Wiley of the

Department of Electricity. Upper left: One of the pedestrian signals. Vpper right:

Combination pedestrian, traffic signal and street sign. Lower left: Another view of

the pedestrian signal. Lower right: I close-up of the pedestrian

"Stop" and "Go" signal.

In addition to the five outside
sources of current supply serving the
station, it is equi])ped with an en-
gine generator of sufficient capacity to
carry the entire load of the building
indefinitely. The eighty-two fire alarm
circuits leave the station through un-
derground cables, which radiate in all
directions and would be unaffected in
a general conflagration.

Police Signal Systems

The Police Department is equipped
with three separate signal systems ; one,
which consists of a private branch tele-
phone exchange, located in the Hall of
Justice, with a local to each district
station and the various branches of the
department. This system was installed
and is maintained bv the Pacific Tele-
])hone and Telegraph Cnmiianv.

Appro.ximately a year ago this de-
partment installed a teletype system,
consisting of a duplicate transmitter
located in the office of the Detective
Bureau, and thirteen receivers located
in the various police district stations.
This system has greatly increased the
efficiency of the Police Department in
that messages pertaining to reports of
all descriptions are sent out simultane-
ously from the Detective Piureau to all
stations, requiring only the length of
time necessary to type the message the
same as on an ordinary typewriter.
Lender the old s^'stem, in the case of a
stolen car being reported, the Detective
Piureau would have to call each station
separatelv by telephone, giving the
license number and description of the
car, which would take from one-half

to three-quarters of an hour in time, to
say nothing of the chances of mistakes
being made due to the human element.

System Unique in San Francisco

The teletype installation is unique in
San Francisco in that several stations
are connected on one circuit, whereas
most other installations are made by
utilizing a separate pair of wires from
the transmitter to each receiving sta-
tion. This complicated the installation
to a very large degree and necessitated
a very fine degree of balancing of the
various circuits to permit the proper
amount of operating current at each

As stated above, the circuits consist
of two wires, one control and one send-
ing wire. When it is desired fo send a
message the operator at the transmitter
throws a switch which actuates a
relay at each receiving set. The op-
erating current of this relay is 60 milli-
amperes. The local contact of the relaj'
starts a motor generator set at each
receiving set which supplies direct cur-
rent for the operation of the magnets
and synchronized motor. The motor
is synchronized by means of a tuning-
fork which is pitched at the same rate,
of vibration as the tuning-fork used on
the transmitter motor. The sending
wire is operated on 55 milliamperes.

The numerals, all letters in the alpha-
bet, the return of the carriage and the
spacing are operated on this one send-
ing wire by means of a combination of
five impulses. The mechanical features

One of the first traffic signals installed in
San Francisco




of these instruments are so well made
tliat they require a minimum amount
of maintenance.

District Station Equipment

Each district station is equipped
with a telephone signal board which
s manufactured by the Department
of Electricity and to which is con-
nected police telephone signal boxes
throughout the district. The boxes
consist of a movement actuated by a
;elf-winding spring which, when pulled
yy an officer, registers on the tape and
jives an audible signal at the board of
he number of the box, the location of
vhich is charted in the station. The
tation officer then depresses a key and
put in telephonic communication with
he officer at the box. The telephone
ircuit of the board is what is known
s a common battery system, which is
upplied by a local storage battery at
;ich station, and which is automatically

'■ of l/i, first tragic signals installed in
San Francisco

' ired by a trickle charger. The tele-
iie circuit in the box is connected
utilizing the well known common
Tpry circuit, which consists of an in-
lon coil and a two micro-farad con-
fer and a Kellogg grah-a-jihone set.
■ officer when reporting in must,
turn in the box, which desig-
> his location, before he can com-
licate with the station officer. There
thirteen district stations equipped
1 telephone signalling boards,
■h are all standardized, and, in case
burn-out or other unforeseen emer-
y, a spare board, which is alwavs




At the upper left Chief Ralph IF. Ifiley (right) and Chief Operator Chester A.
Baltiette are examining the record of a feii: fire alarm calls. The upper right is
another viev; of the Box Signal panel. Left, at the bottom, is a i';c«- of the back of
the Traffic Timer board, shoiving the zairing and the power transmitting shafts, and
III the right the automatic electric Telechrome switch panel, with variable speed

drfve motors.

kept in Stock, can be dispatched to the
station in which the trouble has arisen,
and the new board installed within
thirty minutes.

Traffic Control Problems in
San Francisco

On May 31, 1922, the Department
of Electricity installed the first set of
electrically operated mechanical traffic
signals (which were manufactured in
the department's shop) at the intersec-
tion of Montgomery. New Montgom-
ery, Post and Market Streets. The de-
partment continued to manufacture aiid
install these signals at various inter-
sections throughout the city out of
money appropriated to this department.
It was not until the fiscal year 1925-26
that an appropriation was provided by
the Board of Supervisors to carry on
this work.

In the fiscal year 1928-29 the Board
of Supervisors appropriated approx-
imately S7S,000 for use of this depart-

ment to manufacture a traffic signal
timer, install new cable and reconstruct
Market Street from the Ferry to \'^an
Ness .\venue with new traffic signals
and pedestrian signals.

In July, 1926, a small temporary
synchronized timer, having a capacitv
of four circuits for the downtown dis-
trict and a two-circuit timer for the
oi'.tlying districts, was installed in the
Central Fire Alarm station and the cir-
cuits were carried through spare wires
in e.xisting fire alarm signal cables.
These two temporary timers have been
operating continuously for three vears
handling approximately eighty intersec-
tions throughout the city without a fail-
ure or breakdown, but. due to the fact
that the entire downtown district has
been operating on two circuits, all in-
tersections north of Market Street and
the intersections south of Market Street
on one circuit and Market Street being
on the other circuit, it is obvious that





no flexibility or scientific progressive
timing could be accomplished.

The department has just completed
the manufacture and installation of a
new automatic synchronous traffic sig-
nal timer, having a capacity of 104 cir-
cuits and located in the Central Fire
/Uarm station. This board is separated
into two distinct timers, the No. 1 board
having a capacity of forty circuits and
designed to control the outlying inter-
sections ; the No. 2 board having a ca-
pacity of sixty- four circuits and de-
signed to control the intersections in
the downtown district. These two tim-
ers are operated by two one-half horse-
power 2-phase wound-rotor 220-volt
A. C. motors which are connected up
to 900 to 1 and 1200 to 1 gear re-
ductions. These motors and reduction
boxes are located in the basement and
the shafts on the timers are driven by
means of vertical shafts extending
through the floor of the main office. To
these vertical shafts a 1 to 1 set
of beveled gears tran.smit the power to
eight sets of horizontal shafts on the
back of the timers.

Another set of beveled gears rotate
short stubs which extend through the
front of the board. The contactor
heads are designed with three two-con-
tact plugs which are inserted in three
corresponding jacks in the board. This
type of design permits of flexibility, re-
placing of signal heads by pulling one
head out and inserting a new head in
case of necessity, due to dirty contacts
or any necessary adjustment of the
mechanism. The head is so designed
as to allow a maximum of flexibility.

The ratio of time from one street
to another can be readily changed from

Editor's Note — The new
timer just installed in the Cen-
tral Fire Alarm Station has
been pronounced by Eastern
traffic experts, on visits to
San Francisco, as the most
complete traffic control board
of its kind in the world. Chief
Wiley designed the board.

He also invented the "Stop"
and "Go" traffic signals used
in this city before installation
of his new designs, now in-
stalled throughout the City's
traffic lanes. Combination traf-
fic and pedestrian signals have
been installed as thousands of
San Franciscans witnessed the
transformation of wide traffic
areas into compact safety
zones. These range from Mar-
ket Street and the Embarca-
dero to Van Ness Avenue. The
new traffic signals, in a plan
worked out by Chief Wiley,
automatically will be con-
trolled from the Central Fire
Alarm Station.

30 to 70 per cent of the cycle and both
clearance intervals can be readily
changed from one to twelve seconds.
This extreme flexibility, which is not
to be found in any other timer in use
in the United States, permits the chang-
ing of ratio of time from one street to
another at various times throughout
the day as the traffic load demands, by
the operators at the timer without at-
tention by police officers at the indi-
vidual intersections, due to the peak

iff MMl

in ^ -!:? ^ i!f BH M Wm ■
• • « « • »■» *• • • «*• •jt • •



.It the left is s/ioiiit t/ie Traffic Signal Tiinir, manual control, and tcle/i/ionc panel,

•with Kellogcj Keys and Grah-a-Phone. The picture at the upper right shows the

"Central" desk and master key at the Central Fire .Harm Station. .It the bottom,

right, is a view of the llox Signal "Hospital" panels.

load of traffic on Market Street and
other east and west streets, which, ow-
ing to the topography of the city, are
compelled to carry heavy loads of traf-
fic in the morning and evening hours,
the signals are to be opened at 7 a.m..
with a ratio of 60 per cent on the east
and west streets and 40 per cent on the
north and south streets. This setting
will continue until 9 a.m., at which time
the setting will be changed to 55 per
cent for east and west streets and 45
per cent for north and south streets in
some cases, while other intersections
will be changed to 50 per cent both di-
rections. This setting will continue,
with the exception of Saturdays and
holidays, until 4 :45 p.m., at which time
the signal heads are changed to 60 per
cent east and west and 40 per cent
north and south. After the peak loads,
between 7 p.m. and 12 midnight, there
is little or no crosstown traffic, espe-
cially on Market Street, and the timer
heads at that time are changed to 70
per cent on Market Street, leaving only
30 per cent of the cycle time for the
cross streets.

Electric Time Switches
The two timers operate approx-
imately 95 per cent automatic by
means of six telechrome electric time
switches. The first of these switches
starts the motors at 6:50 a.m., the sec-
ond switch is set for 7 a.m., and ener-
gizes solenoids on the back of the
boards which operate "gang bars." The
operation of these bars mechanicallj'
throws out the figures on the timer
heads which close the necessary contact
and operates the signals. The third
and fourth switches are connected to
other solenoids which, when operated,
automatically cause an impulse to be
sent out at the proper part of the cycle,
which energizes the shutter solenoids
in the signals and the signals are auto-
matically closed for the night. Between
these two time switches and the solen-
oids is placed a small cross connecting
rack. By means of this rack it is pos-
sible to connect any desired circuit to
either the earlier-closing switch, which
closes certain signals down at 6 :15 p.m.,
or the late-closing switch which closes
the remainder of the signals at 12
midnight. The fifth is a four-operation
switch which turns on the lights when
necessary in the vi'inter time at 7 a.m.
in the morning and ofi' at 8:30 or 9^1
a.m., depending upon the length of the^\
days ; and again turns the lights on in
the evening, also depending upon the
length of the days, and off again ati
12 midnight. The sixth switch has been
rebuilt and redesigned by this depart-
ment to operate signals which are con-
nected to variable contacts of the twen-
ty-four hour period.

The object of these signals is to no-
li I y the operators at the time it is neces-



THE M U X I C 1 P A L F. .M 1' I, O V F. F


-ary to change the ratio on the timer
heads due to the change in the traffic
'■ads as explained above.

Can Be Operated Manually

In addition to the automatic time

switches there is a small auxiliary

board equipped with toggle switclies

which permits all the features of the

I timer which are normally operated

I automatically to be operated manually.

This panel is also equipped with a ten-

ircuil telephone board with the neces-

,ry key and voltmeter testing circuit

which f)erTnits telephonic comniunica-

I tion from any traffic signal control box.

one of which is located at each inter-

otion, to the central office. The ad-
1 vantage of this system allows the traf-
fic observer to keep in constant touch
with the central station in case it is
necessar)- to change the timing due to
emergencies or other unforeseen rea-


The department has installed three
v,t:w underground cables with a total

pacity of 450 wires to carr\- the nec-
■^ary circuits to permit the largest de-

ee of flexibility. Each intersection
yjii Market Street, as well as the first
jwo intersections both north and south
of Market Street, is to be controlled bv
kn individual circuit. The cables are
made up of three wraps saturated paper
.\o. 20 gauge conductor with an operat-
ing current to the individual intersec-
'•fin of 150 milliamperes. At each in-

"section there is a control box which

ntains the power compan\-'s meter.

A. C. relays, and the necessary

vitches which will permit an officer to

<e the signals off the automatic con-
irol and operate them manually in case
oi emergencies, or the passing of fire



The signals, a photograph of which
i» shown on this page, consist of two
cylinders, one carrying the signs "Stop"
and "Go," and the other carrying the
shutters. The cylinder is operated bv
a 120-volt A. C. solenoid and the cur-
rent in this solenoid is cut off at the top
of the stroke by means of a switch
fastened to the cylinder. The cylinder
is oscillated back and forth 45° to al-
ternately display the signs "Stop" and
"Go." The signals are closed by means
of a small 120-volt .\. C. solenoid, op-
erating current 240 milliamperes. which
when actuated ties the shutter cylinder
with the signal cylinder and closes the
signal. The first operation of the sig-
nal, when opening in the morning, car-
ries the shutter cylinder back to the
open position, where it stays located
until closed that night. The solenoid
i.i energized for only one-tenth of a

second. .\n intersection of)erating from
7 a.m. to 6:15 p.m.. in the summer
months when the lights are not used,
and the current consumed for the op-
eration of the mechanical signal only,
the total power consumed for thirty
days is one kilowatt hour, or the cost
to the city of three cents per intersec-
tion per month. At the intersections
that c)])erate from 7 a.m. until 12 mid-
night, utilizing lights at night, the av-
erage cost is approximately $1.30 per
month f)er intersection.

Pedestrian Signals

Market Street is unique in traffic and
l>edestrian control in that as the ma-
jority of ihe inter.sections are the inter-
section of five streets, and there are
no two of these intersections that are
uniform or identical.

From a traffic control standpoint,
these intersections have to be treated
in reality as two intersections com-
bined in one. with the result that, in

most cases, the jjcdestrian lanes are
not in close proximity to a traffic sig-
nal, and where they are the traffic sig-
nal displays a misleading signal to the
pedestrian. .Also, due to the fact that
the vehicular traffic from two right-
angle intersections on the north side of
Market Street move at the same time,
and owing to the extreme width i>i
Market .Street with its four street car
lines which, during the peak loads, car-
ry approximately 70 per cent of the
people entering the downtown con-
gested district, it is absolutely essential
that a separate set of different designs
from the vehicular traffic signal be in-
stalled to safely guide the i>edestrian

These pedestrian signals, a photo-
graph of which appears elsewhere in
this issue, were designed and manufac-
tured in the department's shop, and are
at the present time being installed at
each pedestrian lane on Market .Street

^, ■-, -, ■-.

T/ie upper picture is a ^'im: of the partially completed nm- automatic, synchronized
traffic si/inal timer. It has a capacity of 104 circuits. Lo^er left: Close up front Z'iezL-
of traffic signal timer head, and at the right a side vie^- of the traffic signal timer head.




from the Ferry to Van Ness Avenue.
This installation required the inanu-
facture of approximately 180 signals.

The type of lenses used and the de-
sign of these signals are such as to give
an approximate spread of only 12°,
and, with this narrow angle of spread,
the reflected light from these signals is
entirely confined to the width of the
pedestrian lane.

The signal consists of a cast-iron
housing equipped with two green lenses
displaying the word "Go" and two red
lenses displaying the word "Stop."
These lenses are illuminated by means
of a 50- watt lamp for each "Stop" and
"Go" signal, and shows in two direc-

These signals are so synchronized
and coordinated with the traffic signals

that they will give to the pedestrian the
assurance and safety when crossing an
intersection that it is impossible to ob-
tain by the use of vehicular traffic sig-
nals only.

Intersection Islands

The extreme width of several of the
intersectbns on the north side of Mar-
ket Street, such as Drumm and Cali-
fornia, Battery and Bush, Post and
Montgomery, Geary and Kearny, and
Eighth and Market, made it necessary
to raise islands in the center of these
intersections for the safety of the pe-

At some of the foregoing intersec-
tions, before the islands were con-
structed, a pedestrian, after stepping
off the curb, had to traverse a dis-

tance in some cases of 200 feet througli
"No Man's Land" and was more or
less at the mercy of vehicular traffic. I
With the present set-up these ex-i
tremely wide intersections, as far as
the pedestrian is concerned, have been!
cut down to the width of a normal I

These signals are so timed that a pe-
destrian having stepped ofl the curb
immediately prior to the signal chang-
ing to "Stop" will have a reasonable
length of time to reach the curb at the
far side of the intersection before the,
vehicular traffic is resumed.

This will be the first installation
its kind in any city in the United State
as well as in the world, so the write
has been informed.

The Plant Department

of the

Department of Electricity

By Gordon C. Osborne

THE Plant Department is the con-
struction branch of the Depart-
ment of Electricity. Its work consists
of the installation and maintenance of
the Fire Alarm, the Police Telephone
Signal and the Traffic Signal systems.

The Fire Alarm system, the most
important branch of this department,
has grown from a very small system
to one of the largest and most modern
in the country.

When I first entered the Department

One of the speedy ll'liilr trniks used hy the Department of Electricity in construction work

Assistant Chief Electrician
Department of Electricity

of Electricity in February, 1908, there
were fifteen fire-box circuits, 600 fire
alarm boxes, five tapper circuits am
five alarm circuits, which were consid
ered sufficient to protect the City af
that time. In comparison with our pres'
ent day equipment, it was necessary
then for the lineman on trouble detai
at the Fire Alarm office, to walk four
blocks to the stable to get a horse and
buggy with which to get to the loca
tion of the trouble. This necessitatec
a delay of from fifteen to twenty min-
utes and is a serious matter when i
fire alarm line is broken. At the pres
ent time we have a machine used for
night trouble exclusively in readiness
in the garage at the Fire Alarm office,
consequently it takes but a few minutes


THE M U N I CI P A L i: M I' L ( ) Y E E


One of the massive Kleiber trucks used by the Vnderground Department of the Department of Eteitruity. Paul Kleiber, truck
manufacturer, is seen resting his arm on a truck fender. Standing next is Charles Hardy, foreman, and his crevi of

Vnderground liorkers.

•r the lineman to get to the location
aid make the necessan,- repairs. This
i- a most important factor in fire alarm

Fire Alarm Boxes
We have at the present time. 1185
fire alarm boxes which are connected
with fifty-tour circuits. These circuits
are being changed from overhead cir-
cuits to underground circuits as fast as

Online LibrarySan Francisco (Calif.). Board of SupervisorsThe municipal employee (Volume v.3 (Jan. - Sept. 1929)) → online text (page 26 of 84)